MULTIVARIABLE HIGH-AUTHORITY CONTROL OF PLATE-LIKE ACTIVE STRUCTURES

A dynamic modeling capability for plate-like structures with integrated strain actuators is developed using the Rayleigh-Ritz assumed-mode method. The analytical model is utilized to design multi-input, multi-output (MIMO) controllers for active plate-like test articles. High control authority linear quadratic Gaussian (LQG) and optimal projection compensators are designed using a control-law development procedure that combines performance objectives, physical measurements, and LQG design variables in a consistent manner. The control laws are implemented using a real-time digital-control computer. In addition, a stability robustness guideline is developed to predict, a priori, the amount of control authority that can be applied to the test articles without destabilizing high-frequency modes. Closed-loop benchtop experiments are performed to verify the open-loop analytical model, the stability robustness predictions, and the control-law development procedure; the experiments demonstrate the ability of integrated strain actuators to effect high-authority MIMO control on flexible plate-like structures. The results show that considerable disturbance attenuation can be achieved both in the quasi-steady response and over large bandwidths spanning many flexible modes.